Heater fan combination



July 4, 1950 w. H. KnTo ET AL HEATER FAN COMBINATION 5 Sheets-Sheet lFiled Dec. 14, 1946 July 4, 1950 w. H. Kl'rTo l-:TAL 2,513,945

HEATER FAN COMBINATION Filed Dec. 14, 1946 3 Sheets-Sheet 2 July 4, 1950w. H. KlTro ETAL.

mm FAN coimNA'rIoN 3 Sheets-Sheet 3 Filed Dec. 14, 1946 Patented July 4,1950 HEATER FAN COLIBINATION William H. Kitto and Archie J. McMaster,Chicago, Ill., assignors to G-M laboratories, Inc., Chicago, Ill., acorporation of Illinois Application December 14, 1946, Serial No.716,214

(CL 21B-39) 10 Claims.

Our invention relates to a heater fan combina.- tion.

Broadly, the idea of projecting air through a heating element is old andit has also been suggested to remove or de-energize the heating elementso that air at substantially room temperature can be moved by fan bladeaction. Many such heater fan combinations are of a substantiallypermanent nature and have been usefully employed for their intendedpurpose. Attempts to apply the same general idea to portable deviceshave not been eminently satisfactory for a number ci reasons known tothose skilled in the art. In general, portable units have either beenunsuccessful as fans or as heaters or as both; or they have beenrelatively much more expensive than their utility would warrant or theyhave suffered from other defects 'which have rendered them commerciallyunacceptable and they have enjoyed only a limited sale.

The principal object of our invention is the provision oi an improvedheater fan combination.

Another object is the provision of such a unit which is truly portableand which will perform good service as both a fan and heater.

Another object is to produce a portable heater fan combination which can-be simply and inexpensively manufactured and which can be suitably andeasily used ior its intended purpose.

In carrying out our invention, we produce a blower type electric airheater with a removable heater housing having a parting line outside themajor diameter of the fan. Electric heater coils are mounted inside theiront shell and connected to the fan motor case with a cord and plug.The air outlet in the front portion of the shell and the air inlet inthe rear portion of the cover are such that air flow is restricted toapproximately 25% of the volume obtained when the fan is operated as afan and with the heater shell removed. The fan speed is reduced at leastof the order of about 15% when the housing is in position due to thegreatly increased horse power required to pass the air through lthehousing, and the speed and load factors fwork out in such a way thatsubstantially the same effect is obtained as if a two speed motor wereemployed. structurally, the combination of fan, motor housing and fanguard are pivoted to a base, the pivot being between the guard and apair of upstanding arms supported by the base. The motor housingprojects through the rear housing and the housing is mounted outside thefan guard' in such a manner that it also pivots with the remainingportion of the structure when it has been mounted in position. Thus,both the fan and entire heater are adjustable about a horizontal axis sothat the air whether heated or not can -be directed to a particularpoint desired.

Other objects and specific features of the invention will be apparentfrom a consideration of the following detailed description taken withthe accompanying drawings wherein- Fig. 1 is a front elevational view ofthe heater fan combination of our invention with some of the parts shownin dotted lines to illustrate the position thereof and with the housingcarrying the heating elements in position;

Fig. 2 is a rear view thereof;

Fig. 3 is a side elevational view, also with the housing in position;

Fig. 4 is a side elevational view similar to Fig. 3 but with the housingremoved;

Fig. 5 is a iront elevational view of the device with the housingremoved;

Fig. 6 is an enlarged vertical fragmentary sec tional view showing thehousing and the manner of supporting the heating elements therein;

Fig. 7 is a fragmentary, transverse sectional view taken substantiallyalong the line l-'l of Fig. 6;

Fig. 8 is an elevational view of the motor heuslng and contents thereofshown removed from its support;

Fig. 9 is a vertical central sectional view thereof with some of theparts in elevation;

Fig. 10 is a perspective view of a switch ein-l ployed as part of themotor housing assembly;

Fig. 11 is a fragmentary perspective view showing a fastening detail asemployed at the top portion of the housing between the two partsthereof;

Fig. 12 is a fragmentary perspective View showing the construction atthe side edge of the housing where it engages around the fan;

Fig. 13 is an enlarged sectional view partly in elevation showing alatch arrangement employed at the bottom of the housing; ands Fig. 14 isan exploded perspective View showing the details of the latchconstruction.

The embodiment of the invention shown in the drawings comprises a basei6 which may be used to support the fan in a generally upright positionas indicated in Fig. 4, or which may be provided with a usual type ofbayonet slot (note Fig. 2) to support the fan, with or without theheater housing, from a side wall. A yoke Il has associated with it are-enforcing strip I8, the

yoke and re-enforcing strip being together secured to the base bysuitable means, as by screws I8, in the manner particularly indicated inFig. 1 and Fig. 2. The yoke |1 is shapedto form a pair of upstandingarms to the top of which are pivoted a pivot and mounting bracket 2|.The pivot and mounting bracket 2| comprises simply a :dat transversemetal strip having a pair of right angular end portions 2| (see Fig. 4)through which pivot bolts 22 extend and to which such pivot bolts arepreferably substantially permanently secured so that the bracket andpivot lbolts move as a unit. The pvot bolts 22 also extend through theupper ends of the yoke I1 and wing nuts 23 threaded `on the pivot bolts22 can be tightened to secure the pivot and mounting bracket insubstantially movable position with respect to the base.

A cup shaped motor housing 24 has a front closure plate 26 securedthereto by means of a plurality of integral projections 21 whereby toform a firm engagement between the closure plate and the cup shapedhousing and the entire motor housing assembly and contents are mountedto the pivot and mounting bracket 2| by securing such member and theclosure plate 26 together in any suitable manner as by welding,riveting, or the like. The motor housing carries a motor, as showngenerally in Figs. 8 and 9, by means of which a shaft 28 is driven,carrying fan blades 29. The fan blades are protected by a guard 3| ofrelatively heavy wire, the guard 3| comprisng a number of Wire sectionssecured together in the manner shown and fastened to the pivot andmounting bracket 2| by welding. To re-eni'orce and strengthen the lowerportion of the guard, however, a vertically positioned section 3|' issuitably secured to the closure plate 26 by a screw 32 or otherfastening means. The arrangement shown produces a relatively veryinexpensive but, in many respects, advantageous assembly of the fanportion of the device only differing from usual fan constructions inthat the guard, of which the pivot and mounting bracket 2| comprises anintegral part, is pivoted to the base or like support and the motorhousing is secured to the fan guard assembly. By contrast, in the usualconstruction of the prior art, the motor housing is pivoted to a baseand the fan guard is secured to the motor housing. The mechanism, as sofar described, is very easily assembled for manufacturing purposes asWell as for service purposes. It comprises the motor housing assembly,without the closure plate 26, as one sub-assembly; the guard and partsintegral therewith, including the member 2| and closure plate 26, asanother sub-assembly; the base, with its yoke |1, as anothersub-assembly; and the fan blades as the nal sub-assembly. To assemble,the fan blade assembly is slipped into position within the guard 3|, thehousing 24 mounted to the closure plate 26 while at the same timesuitably securing the fan blade assembly to the motor shaft and theportion of the assembly already mounted together then secured in pivotalrelation to the base` I6. The assembly may be carried out in a differentorder of steps than described, but it Will be obvious that we have.provided a compact, inexpensively manufactured, but eiiicient, fandevice as a part of the combination of our present invention.

The heater shell or housing comprises a front shell 33 and rear cover 34secured together ina manner to bedescribed along a parting line 36 (seeFig. 3) which is outsidethe major diameter d of the 1an, and, indeed,just outside the major circumference of the guard 3|.

While the front shell portion of the housing may be formed in variousways, we have found a simple inexpensive method to comprise forming aband 31 having a cross section partly shown in Fig. 6 and securing theends of that band together at asuitable spot in their circumference,preferably coincident with the location of a latch member as will bedescribed. A front portion 38 is suitably formed, as by a drawingoperation, and is extended over the front edge,

of the band 31 in the manner particularly shown in Fig. 6 and the partssuitably secured together as by spot welding, low temperature brazing orthe like. The front cover 38 has an opening 39 partially closed by amesh 4|, the mesh being suitably of the expanded metal type to givemaximum rigidity coupled with suitable openness as desired in thisparticular type of installation. A plurality of guards 42 are secured infront of the mesh 4|, preferably in the manner disclosed in thecopending application of William H. Kitto, Serial No. 678,794, led June24, 1946. These guards are preferably shaped in the manner shown insection in Fig. 6 and in plan in Fig. 7, so that their ends engage andare secured to the front portion 38 of the shell at opposite sides ofthe mesh 4I.

The rear cover 34 generally is shaped like the front portion 38 with,however, a central opening 43 through which the motor housing projectsand a plurality of air admitting openings 44 which are also preferablycovered with a wire mesh similar to the mesh 4|. The rear cover 34 slipsover the edge of the band 31 in the manner particularly indicated inFig. 6 and is secured thereto in the following manner. The top edge ofthe band 31 carries an upwardly extending projection on tongue 46 (seeFigs. 6 and 11) formed suitably by securing to the underside of the banda small plate 41 which carries the tongue 46, the tongue 46, therefore,projecting upwardly permanently through a slot in the band. The rearcover has a slit 48 through which the tongue 46 projects when thehousing is assembled in a manner to be described.

A latch is provided in the bottom portion of the housing constructed inthe following manner: A latch bar 49 (note Figs. 13 and 14) is slidablein a channel member 5|, four outwardly extending ears 52 of which lieagainst the outside bottom surface of the band 31 and are securedtogether as by welding. The member 5|, therefore, not only functions asa portion of a latch but also to secure the ends of the band 31 togetherso as to comprise an integral portion of the construction of thehousing. A latch spring 53 has one end engaged over a projection 54 onthe latch and another end engaging over projection 56 on the channelmember 5|. The

spring is tensioned so as to draw the latch 48 in a left hand direction,looking at Fig. 13. A latch projection 51 is adapted to engage a pro-.iection 58 on the rear cover 34, formed thereon by the simple expedientof cutting a slit in the material comprising the rear cover andpartially drawing the material at one side of the slit out of the planeof the remaining portion of the cover to leave an outwardly extendingprojection. The rear cover 34 is secured to the front shell.' therefore,by first engaging the tongue 46 through the slot 48, then bringing theremaining portion of the rear cover into engagement with the front shelland then withdrawing-the latch by engaging the tail piece 59 and drawingthe latch member 49 backwardly against the tension 'of the spring 53 toengage the projection 51 over the projection 58. The spring 53 is madestrong enough so that the rear cover is rmly held in position in thismanner.

To hold the housing in iixed position with respect to the remainingportion of the fan assembly, the cover 34 and shell 31 are provided withedge slots 6| and lil/respectively (see particularly Fig. 12) whichsurround the pivot bolts 22 when the housing is assembled around the fanguard so that the two portions of the housing, namely, the'band 31 andrear cover 34 are engaged and pinched between the ends 2|' of the pivotand mounting bracket 2| and the inside surfaces of the upwardlyextending arms comprising the yoke |1. Since the motor housing projectsthrough the central opening 43 of the rear cover so as to preventrelative tipping movement between the housing and fan assembly, and therelative positions of the two portions of the device are iixed at thetwo pivot points, the fan and housing will always have the same relationwith respect to each other, and the fan and housing can be moved as aunit to direct heated air in any desired direction.

A heating member comprising strands 63 of coiled resistance wire issecured to the heater shell in the path of air projected by the ianthrough the front opening 39. To support the strands 63 in position, weprovide a pair of cross members 84 and 66 of generally channel shapedcross section as shown particularly in Fig. 6 and having end projections61 (see Fig. 6) shaped to engage the inside surface of the band portion31 of the heater shell where they are spot welded or otherwise attachedto the shell. Thus, the cross members are secured in position in such amanner as to increase the strength and rigidity of the heater shell andat the same time to provide a support for the heater strands 63.

To secure the heating element in position, we provide a plurality ofspool shaped resistance and refractory members 68, suitably porcelain,which, by means of screws 69, are attached to the cross members 64 and66, for instance, in a pattern such as indicated in Fig. l. At oppositeends of the cross member 66,'we provide terminal post assemblies 1|. Thestrands 63 may, therefore, comprise coil sections of a continuous lengthof resistance wire, the ends of which are secured to the terminalassemblies lL t will be noted that there are a greater number oi 'turnsof resistance wire at the outside portion of the opening 39 than at thecenter portion thereof. We have, by the means indicated, been able sojtorelate the coils of resistance wire to the air passing therethrough,that the air is of substantially uniform temperature as it emerges fromthe opening 39. The strands 63 are supported closer together at thepoint of maximum amount of air ow, but the heating surface at aparticular point may be controlled in various ways, as, for example, byproviding a greater number of coils in the strand and in other waysknown to those skilled in the art. We have found a very simple method ofproducing the coiled strands to be to grasp the central portion oi awire section with a suitable tool and twist the same while guiding thewire so that the helices are formed with opposite inclinations at thetwo sides of the point at which the wire is grasped. En this way, it isvery simple to coil an intermediate section of a single strand andcontrol the number of turns, thereby in a simple Cai and inexpensive wayproducing a single strand with intermediate coil strand sectionsdisposed between the fastening loops as clearly shown in Fig. 1.

The heating element is connected into the electrical circuit by means oftwo properly insulated lead-in wires 12 which are joined to form asingle strand double conductor 13 which passes through a grommet 14 inthe shell housing and leads to a suitable plug 16 for connection to asource of power in a manner which will be described.

A suitable motor for driving the fan is mounted within the cup shapedhousing 24 and comprising a stator consisting of a coil 11 carried on alaminated core 'i8 secured to the cup shaped motor housing by suitablemeans including mounting screws 19. A suitable rotor, which is not shownin detail in the drawings, carries the shaft 28 journalled in suitablebearings 8| and 82 formed in such a manner as to act as both radial andthrust bearings. These bearings are of such a type as to receive oilfrom time to time and to deliver oil thereto, we provide a pair of oiltubes 83 suitably formed of plastic and having supporting terminals 84,the Shanks of which extend through holes in the housing, and the flatheads of which are in part engaged by the iiange of a switch 86 to holdthe oil tubes in position.v The supporting terminals 84 are in thenature -of hollow rivets which are slightly pinched in at their lowerends as indicated to grasp the plastic tubes and produce substantially aunitary assembly. By delivering oil through the members 84, it passesthe tubes 83 and flows to the bearings through apertures thereinprovided for the purpose. The electric switch 86 is disposed in arectangular` opening at the top of the motor housing and has springmembers 81 at each side thereof so that it can be snapped into positionand vwill be held by the springs `81 or can be snapped out of positionto dissociate it from the housing. At a. corresponding position, nearthe bottom of the motor housing, is a combination socket and terminusmember 88 held in position by a pair of fastening screws 89 which engagea mounting bracket 9 As noted particularly by reference to Fig. 8, theplug 1E engages in the socket 88 to provide a source of electricalenergy to the heating coils. A cord 92 is adapted to be plugged in in asuitable manner to a source of power and is suitably led into the motornousing 24 where one of its conductors 93 is connected to one side ofthe switch 8B and another of its conductors 9i! is connected to oneterminal of the coil l1. A conductor 9S leads from the opposite switchterminal to the opposite side of the coil l?, and the coil and terminalsof sccket or receptacle S8 are suitably connected in parallel so thatwhen the coil 11 is energized the receptacle 38 will also be live. Thusthe circuit comprises the switch v3S and coil l1 connected in series andthe receptacle .38 connected parallel to the coil so that by operatingthe switch 36 to On position both the motor and heating element areenergized ir" the heating elements are connected into the circuit, or ifthe heating elements are not connected into the circuit, then the motorwill nevertheless be energized and can be operated without the heatingcoil. The heating element, however, cannot be heated except when the fanis operated.

t the rear of the motor housing, aligned with the coil l1, we provide a,plurality of ioni/ers 9i so that some or the air moved by the fan willpass through the motor housing and be directed against the portion ofthe motor developing the greatest amount of heat.

4 It will be seen from the above description that the combination deviceof our present invention can equally well operate as a fan unit orheater unit and in any case is adjustable and simply and easily employedv,'ust as-if it had been designed to perform only a'single function. Itwill be noted that the top of-the housing is provided with a handle 98for easy portability when the device is used as a heater, while theguard may act as a handle to carry the fan when the heater housing isnot in position. While normally the device is expected to stand on itsbase, it may be suitably supported, as by means of the bayonet slot99'indicated in Fig. 2, in which case the base will lie in a verticalVplane and the fan motor and heater housing (if in position) may berotated a major portion of/ 90 degrees about the pivots to direct air,heated or otherwise, substantially in a horizontal direction.

If the device is to be used only as a fan, it will deliver unheated airif the plug IIB be removed, but preferably the entire housing is removedbecause there is a substantially greater delivery oi air under suchcircumstances. To remove the housing, the plug is first removed, thelatch at the bottom of the housing disconnected, the wing nuts loosened,and the rear cover 34 removed by first separating it at the bottom andthen lifting the slo-t away from the tongue at the top of the housing.The cord is passed through the central opening of the rear cover and itis removed in its entirety. The front housing is then removed by merelyseparating it from -the'pivots, and the wing nuts are then tightenedwith the fan in suitable position for operation. The housing may bestoredtempoiarily with the rearcover and heater shell latched togetherin the same manner as when in position around the fan blades. To replacethe housing, the reverse' steps are employed. The wing nuts are firstloosened, the fan and guard placed in the heater shell, suitably byplacing the heater shell on the lap and placing the fan face downwardlyin the shell, the cord and motor housing then extended through thecentral rear opening of the rear cover, and the rear cover then latchedto the housing in the intended manner. The band 31 and rear cover 34will, automatically, be disposed between the pivot and mounting bracket2l and yoke l1 when assembled in this manner, and when the wing nuts arefastened the assembly will be complete except for insertion of the plug16 which is required to deliver current to the heating elements.

The combination of our invention may be constructed in various ways andthe capacity may be varied. We have obtained good results by providing aconstruction in which approximately five hundred cubic feet of air perminute are displaced by the ian without the heater housing andapproximately one hundred thirty-five cubic feet of air per minute whenthe heater housing is in position. |The flow of air through the housingshould preferably be restricted to somewhere between about 20% and 40%of that of full fan capacity without the housing and suitably about whendelivering values of the order described. We have found that byrestricting the air intake in the manner described, the fan speed isreduced at least of lthe order of about 15% of full speed without thehousing. In some respects this produces the same general effect asobtained by the use of a two speed motor; in other words, permitsobtaining the same general advantages without the attendant costs.

There are many details and advantages in the construction of ourinvention which will be recognized by those skilled in the art but whichscrews of the switch, and by forming them oiv plastic the possibility ofa short circuit or arcing is greatly reduced., The simple manner ofsecuring the metal terminals and holding the tubes in position is alsoadvantageous. It should be noted, also, that the cord 'I3 -is preferablymade short enough so that it is impossible to remove tlsie housingwithout rst disconnecting the plug Some of` the remaining details,particularly as to motor construction and the like may be made the subject matter of separate applications. The scope of the invention asdirected to the combination fan and heater is defined in the claims.

What we claim as new and desire to protect by Letters Patent of theUnited States is as follows:

1. In a heater fan combination, a fan structure including a base, motorhousing, fan blades and blade guards, operable as a fan, and a pluralpart heater housing entirely surrounding the fan and guards therefor,the parts being separable at a point outside the major diameter of theian, the housing having a heating element and means to deliver currentthereto, the said housing being apertured to passsubstantially less airthan that normally delivered by the fan with the housing removed.

2. A heater fan as defined in claim 1 where- 1 in said heating elementis mounted on the inthe heating element, the said receptacle and motorbeing in parallel series relation with the switch so that both areenergized simultaneously.

5. A heater ian as defined in claim 1 wherein said motor housingcontains a motor, switch and receptacle for a heater plug, and an oiltube having a top flange engaged by the switch to hold the oil tubes inposition to deliver oil to the motor.

6. In a heater fan combination, a fan structure including a base, motorhousing, fan blades and blade guards, operable as a fan, and a pluralpart heater housing releasably secured together about the said guardalong a peripheral line outside the major diameter of the fan, thehousing having a heating element and means to deliver current thereto,said heating element being nonuniformly distributed in the path of theair, with a greater concentration of heat at places of maximum air iiow,so that the air as discharged is substantially uniformly heated. v 7. Ina heater fan, as defined in claim 1, wherein the housing carries a cableand plug for energizing the heating element, said cable being of Vsuchlength that it is necessary to remove the plug from its receptaclebefore the heater housing can be removed from the combination.

8. In a heater fan combination, a fan structure including a base, motorhousing, fan blades and blade guards. operable as a Ian, and a pluralpart heater housing releasably secured together about the said guardalong a peripheral line outside the major diameter of the fan, thehousing having a heating element and meansto deliver current thereto,the said housing being apertured to pass substantially less air thanthat normally delivered by the fan with the housing removed, saidhousing having a cylindrical portion rolled from sheet metal, the endsof which are spaced from each other along a meridian of the cylinder,but secured together by having a latch housing attached thereto, thehousing containing a spring and latch functioning to secure separableportions of the housing together.

9. In a heater fan combination. a fan having a support, a motor andmotor housing adjustable with respect to the support. and fan bladesdriven by said motor, all operable asa normal air moving fan. and ahousing entirely surrounding said fan blades and separable at its majordiameter. said housing being apertured to permit ilow of airtherethrough at not more than about seventyve percent capacity of thefan without the housing, and aheatlng element carried by the housing anddisposed to heat substantially equally all air passing lthrough thesame.

10. A heater-fan combination comprising a base having a pair ofupstanding arms, a mounting bracket having :pivot bolts extending intosaid arms, a motor and housing secured to said mounting bracket, fanblades driven by said motor, a guard surrounding said i'an blades andsecured l0 to the mounting bracket, a housing having two principal partssecured together about substantially their major diameter outside themajoi diameter of the fan so as to enclose the fan blades and guard, onesuch housing part being apertured to permit the motor housing to projecttherethrough and the other carrying a heating element along the generalaxis of the fan, the housing being apertured to Dass air equivalent tonot more than about seventy-tive percent capacity of the fan, the saidhousing being disposed between said mounting bracket and upstanding armswhen in assembled relation around the fan blades, and nuts threaded onthe said pivot bolts to hold the fan and .housing in adjusted rela- Ition, the housing being separable and removable and the said nutsadapted to secure the mounting bracket alone when the tan is employedwithout the housing.

WILLIAM H. KITIO. ARCHIE J. MCMASTER.

REFERENCES CITED The following references are ci' record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 1,425,546 Russell Aug. 15, 19221,633,801 Williams June 28, 1927 1,958,007 MacDougall May 8, 19342,149,689 Smith et al. Mar. 7, 1939 2,274,935 Naul Mar. 3, 1942

